Melbourne - A car ploughed into pedestrians at a crowded intersection in the Australian city of Melbourne on Thursday, injuring up to 15 people, police said, adding they had arrested the driver and a second man.

Police did not suggest a possible motive for the incident, which had chilling echoes of several attacks by Islamist militants in various parts of the world over the past year or two.

The Victoria State ambulance service said it had taken 13 people to hospital, including a pre-school child with a serious head injury, while two people were being treated at the scene.

"The driver of the vehicle and a second man have been arrested and are in police custody," police said in a statement, adding that a crime scene had been established.

Picture: Australian Broadcast Corp. via AP

In January, four people were killed and more than 20 injured when a man deliberately drove into pedestrians at a spot just a few hundred metres away from the Thursday incident.

Police said the January incident was not terrorism-related.

Major streets in Australian cities have been packed with holiday shoppers this week.

The incident took place on Flinders street, a major road that runs alongside the Yarra River.

A Reuters witness said a white sports utility vehicle came to a halt at a busy intersection where commuters enter and exit the busy city Flinders Street railway station.

"It's delayed traffic, trains, trams, everyone's getting diverted," the Reuters witness said, who saw four police cars, two paramedic vehicles, one ambulance and a fire truck at the scene.